EURURO Vol. 72 No. 2

Platinum Priority – Editorial

Referring to the article published on pp. 177–188 of this issue

Prostate Imaging-Reporting and Data System Version 2 and

the Implementation of High-quality Prostate Magnetic

Resonance Imaging

Jelle Barentsz

a , * ,

Maarten de Rooij

a ,

Geert Villeirs

b ,

Jeffrey Weinreb

Department of Radiology and Nuclear Medicine, Radboud University Medical Center, Nijmegen, The Netherlands;

Division of Genitourinary Radiology,

Ghent University Hospital, Ghent, Belgium;

Department of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA

Introduction

Multiparametric magnetic resonance imaging (mpMRI) is

now a well-established tool to improve the diagnosis of

prostate cancer (PCa). Several meta-analyses show that the

use of mpMRI and mpMRI-targeted biopsy in men with a

suspicion of PCa yields higher detection of clinically

significant PCa than the current standard using systematic

transrectal ultrasound-guided biopsy (TRUS-GB) and

reduces the detection of indolent PCa

[1,2] .

Further support

for these concepts has come from the results of the PROMIS

project, a large multi-institutional trial in the UK

[3]

. There-

fore, when used as a triage test, mpMRI could be an

important contributor in causing a shift in the current

paradigm of overdiagnosis and overtreatment of PCa.

However, as pointed out in this issue of

European Urology

by Woo and coworkers

[4]

, there is significant variability in

published results. For example, there is a highly variable

negative predictive value for the exclusion of clinically

significant PCa, ranging from 63% to 98%

[5]

. Among the

possible explanations for these variable results are differ-

ences in patient populations, reference standards, image

acquisition techniques, image quality, interpretation crite-

ria, reader experience, and inter-reader variability.

Considering the high disease frequency and the growing

importance of prostate mpMRI, the entire PCa health care

community, including radiologists, urologists, (radiation)

oncologists, and pathologists, must speak the same

‘‘language’’ and have access to reliable high-quality mpMRI

exams. To harmonize practices, in 2012 the European

Society of Urogenital Radiology (ESUR) published guide-

lines, including a scoring system, called Prostate Imaging-

Reporting and Data System (PI-RADS) version 1

[6] .

On the basis of additional experience and rapid progress

in the field, PI-RADS version 2 was developed by the ESUR,

the American College of Radiology (ACR), and the Interna-

tional Working group of the AdMeTEch foundation, and was

published in 2016

[7] .

PI-RADSv2 was designed to promote

global standardization and diminish variation in the

acquisition, interpretation, and reporting of prostate mpMRI

examinations. It was intended to be a ‘‘living’’ document that

would need to be tested and validated for specific clinical

applications. The expectation was that it would continue to

evolve as clinical experience and scientific data accrued.

In the excellent systematic review and diagnostic meta-

analysis by Woo et al

[4]

, PI-RADSv2 had high pooled

sensitivity of 89% and specificity of 73%. In the studies in

which head-to-head comparison was possible, the sensitivi-

ty of PI-RADSv2 was significantly better than PI-RADSv1

(95% vs 88%) with equal specificity (73% vs 75%), thus

supporting the use of PI-RADSv2. On the basis of their

findings, the authors propose some areas for improvement in

PI-RADS. This adds to the growing literature based on

experience and research that has highlighted the strengths

of PI-RADSv2 and areas that need refinement, improvement,

or additions. Some of these include clarification of PI-RADS

assessment category (1-5) cutoff values for different clinical

scenarios for detecting PCa (eg, diagnosis in biopsy-naı¨ve

E U R O P E A N U R O L O G Y 7 2 ( 2 0 1 7 ) 1 8 9 – 1 9 1

ava ilable at

www.sciencedirect.com

journal homepage:

www.eu ropeanurology.com

DOI of original article:

http://dx.doi.org/10.1016/j.eururo.2017.01.042

* Corresponding author. Department of Radiology and Nuclear Medicine, Radboud University Medical Center, P.O. Box 9101, Nijmegen,

The Netherlands. Tel. +31 24 3619196.

E-mail address:

jelle.barentsz@radboudumc.nl

(J. Barentsz).

http://dx.doi.org/10.1016/j.eururo.2017.02.030

0302-2838/